Experimental observations of patchy reconnections associated with the three-dimensional tearing instability

Journal Article · Fri Mar 01 04:00:00 EST 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/90JA02630· OSTI ID:5377203

Gekelman, W; Pfister, H ^[1]; Kan, J R ^[2]

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1. Univ. of California, Los Angeles (USA)
2. Univ. of Alaska, Fairbanks (USA)

Experiments on tearing of a thin current sheet are performed in a collisionless laboratory plasma. The tearing of the finite-dimension current sheet (L{sub x} = 40 cm, L{sub y} = 100 cm, L{sub z} {approx} 1.3 cm) is fully three-dimensional (3-D). The 3-D tearing is observed to lead to patchy reconnection. The wavelengths of the most unstable mode of the 3-D tearing satisfy the scaling relationship: {lambda}{sub y} {approx} {lambda}{sub x} {approx} 30 L{sub z}. The e-folding time of the 3-D tearing is about 50 percent longer than that of the 2-D tearing: {tau}(3-D)/{tau}(2-D) {approx} 1.6. The sites of the patchy reconnections are centered on the X line segments which are located in the current density minima. The experimental results are consistent with the observational model proposed by Russell and Elphic (1979) for the reconnection at the dayside magnetopause, known as the elbow-shaped flux transfer events (FTEs). The results also support the theoretical idea that elbow-shaped FTEs can be produced by the 3-D tearing, resulting in patchy and intermittent reconnections driven by the solar wind as proposed by Kan (1988).

• OSTI ID: 5377203
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:A3; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COLLISIONLESS PLASMA
COMPARATIVE EVALUATIONS
EVALUATION
INSTABILITY
LABORATORIES
MAGNETIC FLUX
MAGNETIC RECONNECTION
MAGNETOPAUSE
MATHEMATICAL MODELS
PLASMA
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
SOLAR ACTIVITY
SOLAR WIND
TEARING INSTABILITY
THREE-DIMENSIONAL CALCULATIONS